1. Field of the Invention
The present invention generally relates to a diving stick, and in particular to a diving stick made of a material soft and pliable enough to prevent injury to a person by impalement.
2. Description of the Related Art
Diving sticks are sticks that include weights at one end so that, when tossed into a swimming pool, the sticks will stand upright on the pool floor for easy retrieval by a diver. Such sticks may be used for recreation or for the purpose of enhancing diving skills.
Recently, it has become apparent that conventional dive sticks can cause injury by impaling persons who land on them. While only seven children have been reported injured according to an article in The Washington Post dated Jun. 25, 1999, the nature of the injuries, rectal or vaginal impalement, is so severe that the sticks are considered to be a serious hazard, and it has been proposed to completely ban the import and manufacture of diving sticks.
Conventionally, diving sticks are made of a rigid, water impermeable material and must be partially filled with ballast having sufficient weight to cause the stick to sink, weighted end first, and stand upright at the bottom of the pool. For example, Swimline offers a "Promotional Style Dive Sticks Underwater Game" made up of sand-filled, weighted sticks that are said to stand upright on the pool floor for easy retrieval, while Shelcore Toys, Inc. has in the past offered non-weighted diving sticks made of a relatively light material that is pre-filled with water to a desired level in order to overcome the buoyancy of the material. Such sticks are inexpensive and effective for their intended purpose of providing an object that can easily be retrieved from the bottom of the pool but depend on the impermeability and rigidity of the material to enable the sticks to perform in the intended manner and therefore present an inherent risk of impalement, leading to the proposals to ban all diving sticks.
One possible solution to the problem of impalements is simply to make the tubes of a soft material, but available soft materials such as cloth or fabric and PVC are generally too light to sink, even when filled with water, and when weighted sufficiently to overcome the natural buoyancy of the material, become just as hazardous as the more rigid but lighter conventional diving sticks. In addition, a certain amount of air must be retained in the diving stick to permit it to stand upright at the bottom of the pool so that it can easily be grasped by a diver, which precludes use of conventional soft, water permeable toys as diving sticks. While valves, tubes, and the like offer the possibility of buoyancy control and could be used in relatively soft objects, such arrangements are too complex to be commercially viable, and are thus not suitable for use in the context of the invention. As a result, none of the currently available diving sticks are made of a soft material.
Numerous underwater toys underwater toys with provision for controlling or varying buoyancy and orientation have also previously been proposed or sold, but none are suitable for use as diving sticks. In most diving toys having a variable buoyancy, the rate or level of descent is controlled by adding air through a straw, tube, or closeable valve structure, and thus are too complex to be commercially viable for use a diving sticks, and/or are inconvenient to use.
For example, U.S. Pat. Nos. 4,662,627, 3,713,250, 3,392,483, and 2,297,727 disclose toys that require air hoses or straws for buoyancy control, and thus are not only relatively complex in addition to being unsuitable for use in deep water. Similarly, U.S. Pat. No. 5,722,871 discloses a variable buoyancy device that requires a relatively complex manually-controlled valve structure to control buoyancy, and U.S. Pat. No. 4,198,780 discloses a toy that utilizes gas generated internally by wetting baking powder in a cavity in the toy. On the other hand, U.S. Pat. No. 5,810,364, which describes a treasure chest toy that must be filled with sand by a user before being tossed into a swimming pool, and which would present the same impalement hazard as the conventional diving sticks if shaped in a similar manner.
At present, there is an urgent need for improvements in the safety of diving sticks, and in particular the provision of a soft, pliable diving stick that cannot impale a person, and yet that has an elongate shape so that it can easily be grasped and that functions in the same way as a conventional diving stick.